According to a Government Report, All of the Following Were

According to a government report, all of the following were found to be key similarities among 37 school violence incidents that happened between 1974 and 2000 except

A) incidents of targeted violence at school are sudden, impulsive acts
B) prior to most incidents, other people knew about the attacker's idea and/or plan to attack
C) there is no accurate or useful profile of students who engage in targeted school violence
D) most attackers engaged in some behavior prior to the incident that caused
Others concern or indicated a need for help
E) none of the above